title: Arabidopsis thaliana 26S proteasome subunits RPT2a and RPT5a are crucial for zinc deficiency-tolerance.
abstract: RPTs (regulatory particle triple-A-ATPase) are components of 26S proteasome. We found novel roles of RPT2a and RPT5a in Zn deficiency-tolerance. Arabidopsis thaliana mutants carrying T-DNA in RPT2a and RPT5a were more sensitive to Zn deficiency than the wild-type. In the rpt mutants, the shoot Zn contents were similar to those of the wild-type. Transcripts of Zn deficiency-inducible genes were highly accumulated in the rpt mutants, suggesting that the rpt mutants suffer from various Zn deficiency symptoms, although the Zn levels are not reduced. Lipid peroxidation levels, known to be increased under Zn deficiency, were higher in the rpt mutants than in the wild-type. Poly-ubiquitinated proteins were accumulated upon exposure to Zn deficiency, especially in the rpt mutants. Overall, this study indicates that RPT2a and RPT5a are involved in Zn deficiency-tolerance, possibly through alleviation of oxidative stresses and/or processing of poly-ubiquitinated proteins.
authors.affiliation: Department of Biotechnology, Graduate School of Agricultural and Life Sciences, The University of Tokyo, Tokyo, Japan.
authors.forename: Takuya
authors.initials: T
authors.lastname: Sakamoto
authors.forename: Takehiro
authors.initials: T
authors.lastname: Kamiya
authors.forename: Kaori
authors.initials: K
authors.lastname: Sako
authors.forename: Junji
authors.initials: J
authors.lastname: Yamaguchi
authors.forename: Mutsumi
authors.initials: M
authors.lastname: Yamagami
authors.forename: Toru
authors.initials: T
authors.lastname: Fujiwara
mesh_terms: D000251:Adenosine Triphosphatases / Q000235:genetics / Q000378:metabolism*; D017360:Arabidopsis / Q000235:genetics / Q000378:metabolism; D029681:Arabidopsis Proteins / Q000235:genetics / Q000378:metabolism*; D004269:DNA, Bacterial / Q000235:genetics / Q000378:metabolism; D015870:Gene Expression; D015227:Lipid Peroxidation; D018384:Oxidative Stress; D018520:Plant Shoots / Q000235:genetics / Q000378:metabolism; D016133:Polymerase Chain Reaction; D025821:Polyubiquitin / Q000032:analysis; D046988:Proteasome Endopeptidase Complex / Q000235:genetics / Q000378:metabolism*; D021122:Protein Subunits / Q000235:genetics / Q000378:metabolism*; D012333:RNA, Messenger / Q000032:analysis; D054875:Ubiquitination; D015032:Zinc / Q000172:deficiency
chemical_list: D029681:Arabidopsis Proteins; D004269:DNA, Bacterial; D021122:Protein Subunits; D012333:RNA, Messenger; C487429:RPT2a protein, Arabidopsis; C036483:T-DNA; D025821:Polyubiquitin; D046988:Proteasome Endopeptidase Complex; C061553:ATP dependent 26S protease; D000251:Adenosine Triphosphatases; C541999:RPT5a protein, Arabidopsis; D015032:Zinc